Gracilidris pombero Wild & Cuezzo 2006
- Rediscovery of a fossil dolichoderine ant lineage (Hymenoptera: Formicidae: Dolichoderinae) and a description of a new genus from South America.
- Gracilidris pombero
Biology In the two collection series where nesting information was noted (the Paraguayan type series and the Mato Grosso series), colonies were in soil with the nest entrance consisting of a small earthen turret. The turret of the type series nest in Paraguay was only a few millimeters tall and opened at ground level on one side (Fig. 9), so that the nest entrance was cryptic and concealed from above. There appeared to be only one nest entrance. A low level of activity at the entrance of the type series nest and the small number of workers (n = 25) collected during a partial nest excavation suggests a small colony size. The collection records of G. pombero indicate that it inhabits low scrub forests of the type found in cerrado and chaco habitats. The specimens from Maranhao were collected at a sardine bait in cerrado scrub forest near the edge of a soybean field. The specimen from Bahia, Brazil was collected in a small primary forest fragment in a Cocoa plantation. The Mato Grosso, Brazil collection was from grazed cerrado, and the Paraguayan type series came from a lightly grazed Copernicia alba palm forest in the humid chaco. Gracilidris ants are probably noctural, which may partly explain their rarity in collections. At the type locality, single foraging workers were collected at dusk and after dark on two separate nights, and visual searches and baits during the day at the same location did not yield any workers. In the field, workers appear elongate, their gaster held horizontally (Fig. 10), and their movements are smooth and deliberate. Reproductive castes, brood, colony structure, and life history are unknown.
Etymology Pombero is a mythical nocturnal figure in Guarani folklore. The name is applied here as a noun in apposition in reference to the nocturnal activity pattern of this species.
Additional material examined Argentina: Santiago del Estero: Copo National Parq. (5 w, IFML). Brazil: Bahia: Ilheus, CEPEC, specimen not directly examined, (photographic internet record, # 4830: http: // research. amnh. org / entomology / social _ insects / tempcepecline. html, available in 2002 and apparently offline as of August 2005). Maranhao: Balsas, Gerais de Balsas 08 ° 34 ’ S 46 ° 42.6 ’ W xi. 1999 - iii. 2000, Brandao et al (2 w, MZSP). Mato Grosso: Mpio. Varzea Grande, Souza Lima, 25. i. 1985, J. C. Trager (3 w, MZSP). Sao Paulo: Agudos, xii. 1957, C. Gilbert (2 w, MZSP).